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我正在使用Hibernate 5.0.2.Final與數據源連接(在Tomcat 8.0.15上),並開始問我自己是否有必要關閉Session而且還需要SessionFactory?會話和工廠應該關閉嗎?
現在它看起來是這樣的:
public class HibernateUtil {
private static final SessionFactory sessionFactory;
static {
try {
Configuration cfg = new Configuration();
sessionFactory = cfg.configure("hibernate.cfg.xml").buildSessionFactory();
} catch (Throwable ex) {
Logger.getLogger(HibernateUtil.class.getName()).log(Level.SEVERE, null, ex);
throw new ExceptionInInitializerError(ex);
}
}
public static SessionFactory getSessionFactory() {
return sessionFactory;
}
}
我猶豫着:
public static List<HibernateList> getHibernateList() {
Session session = null;
final String hql = "SELECT H FROM myhibernate.MyHibernate";
try {
SessionFactory factory = HibernateUtil.getSessionFactory();
session = factory.openSession();
session.beginTransaction();
Query query = session.createQuery(hql);
return query.list();
} catch (HibernateException hibex) {
Logger.getLogger(Hibernatepicker.class.getName()).log(Level.INFO, null, hql);
Logger.getLogger(Hibernatepicker.class.getName()).log(Level.SEVERE, null, hibex);
} finally {
try {
if (session != null) {
session.close();
}
} catch (HibernateException hibex) {
}//Nothing I could do...
}
return null;
}
從hibernate.cfg.xml中
<property name="hibernate.connection.datasource">java:comp/env/jdbc/sqlserv</property>
<property name="current_session_context_class">thread</property>
<property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>
<property name="hbm2ddl.auto">auto</property>
<property name="show_sql">false</property>
<property name="hibernate.generate_statistics">true</property>
而且HibernateUtil中的一些細節有必要或不要在finally塊中調用此方法,而不是僅關閉會話:
public static void disconnect(Session session, SessionFactory factory) {
try {
if (session != null) {
session.close();
} else {
Logger.getLogger(HibernateUtil.class.getName()).log(Level.INFO, null, "Session is Null");
}
} catch (HibernateException | NullPointerException hibex) {
Logger.getLogger(HibernateUtil.class.getName()).log(Level.INFO, null, "Couldn't close session, but there's nothing we can do...");
Logger.getLogger(HibernateUtil.class.getName()).log(Level.SEVERE, null, hibex);
}
try {
if (factory != null) {
factory.close();
} else {
Logger.getLogger(HibernateUtil.class.getName()).log(Level.INFO, null, "Factory is Null");
}
} catch (HibernateException | NullPointerException hibex) {
Logger.getLogger(HibernateUtil.class.getName()).log(Level.INFO, null, "Couldn't close session, but there's nothing we can do...");
Logger.getLogger(HibernateUtil.class.getName()).log(Level.SEVERE, null, hibex);
}
}
太好了,謝謝你的快速響應。有什麼方法可以確保它剛剛初始化一次? – Qohelet
@Qohelet是的。您可以使用Singleton Pattern來確保單個初始化,或者如果您使用任何CDI環境(如Spring等),它們都支持這種內置的功能。 – bhdrkn
我的HibernateUtil看起來有點像Singelton-ish ...?我的假設是正確的嗎? – Qohelet